Water is the important substantial foundation of social and economic development. In view of its importance, establishing an appropriate model to predict the supply and demand of water in the future is vitally necessary. By analyzing the future situation, we can take some intervention measures as early as possible. Firstly, we build a simulation system model based on the Systems Dynamics (SD). There are two reasonable indicators, including the amount of the primary balance (PB) and the amount of the secondary balance (SB), to reflect the relation between the supply and demand of water. PB reflects the water shortage degree and SB reflects the dependent degree on the water resources in other regions. Based on 48 variables and four subsystems, the SD model can accurately and dynamically simulate the change of the real system. Then, we propose an intervention, it mainly contains two aspects. One is to reduce the exploitation of the groundwater, the other one is to strengthen management and increase the advanced equipment.